Catalytic oxidation of hydrocarbons



Patented Nov. 1, 1949 CATALYTIC OXIDATION OF HYDROCARBONS George W.Hearne," El Cen'ito, and Merrill L.

Adams, Modesto, Calii'., assignors to Shell Development Company, SanFrancisco, Calil'., a

corporation of Delaware No Drawing. Application June 18, 1946, SerialNo. 677,530

16 Claims. (Cl. 260-604) This invention relates to the oxidation ofolefins containing at least three carbon atoms to unsaturated carbonyliccompounds of the group consisting of the unsaturated aldehydes and theunsaturated ketones containing an olefinic linkage between two carbonatoms of aliphatic character,

one of which is linked directly to the carbon atom of the carbonylgroup. More particularly, the present invention relates to the catalyticoxidation of the defined class of olefins with the aid of a solidcuprous oxide catalyst, and in particular to such catalytic oxidation inthe presence of a minute amount of a compound of chlorine, whereby theyields of the unsaturated carbonylic compounds are desirably increasedover those obtained in the absence of the compound-of chlorine.

This application is a continuation-in-part of our prior, copendingapplication Serial No. 476,786, filed February 22, 1943, now abandoned.In the indicated prior application there is disclosed a process whichcomprises contacting an olefin of at least three carbon atoms withcuprous oxide or a solid contact mass comprising cuprous oxide, in thepresence of oxygen under conditions at which a substantial amount of thetreated olefin is oxidized to an unsaturated carbonylic compoundcontaining the same number of carbon atoms per molecule as the olefin.

In accordance with the present invention, it has been discovered thatthe oxidation of an olefin containing at least three carbon atoms in thepresence of a solid cuprous oxide catalyst to provide an unsaturatedcarbonylic compound containing the same number of carbon atoms, may beeffected with substantially increased yields of the carbonylic compoundby conducting the oxidation in the presence of a minute amount of acompound of chlorine, preferably an aliphatic organic compound ofchlorine, such as isopropyl chloride. In accordance with the process ofthe present invention, the provision and regulation of such minuteamounts of a compound of chlorine in the reaction mixture results in asubstantially greater conversion of consumed olefin to unsaturatedcarbonylic compound than is obtained under the otherwise existingconditions in the absence of the compound of chlorine.

The process of the present invention is applicable generally to theconversion of olefins of three or more carbon atoms to unsaturatedcarbonylic compounds of the class consisting of the unsaturatedaldehydes and the unsaturated ketones by oxidation in the presence of asolid cuprous oxide catalyst. By the term olefin as used herein and inthe appended claims is meant the open-chain as well as cyclic oleflns.Among the many olefinic.

compounds which are adapted for use as starting materials, the followingmay be mentioned: propylene, butene-l, butene-Z, isobutylene,diisobutylene, pentene-l, pentene-2, 3-methyl-butene-1,

2-methyl-butene-2, hexene-l, hexene-Z, 4- methyl-pentene-l,3,3-dimethyl-butene-1, 4- methyl-pentene-2, octene-l, cyclopentene,cyclohexene, 3'-methyl-cyclohexene, etc. These compounds and theirvarious homologs may be substituted in the nucleus and/or in thesubstituents in various degrees by straight chain alicyclic and/orheterocyclic radicals. The olefins may be treated individually or asmixtures with each other or with the corresponding or other saturatedorganic compounds. When treated in mixtures, for example, with thecorresponding paraflin, the parafiin may remain substantially, if notwholly, unaffected. In other words, by the present process it ispossible to selectively oxidize olefins, saturated compounds if presentacting merely as diluents. Conversions efiectible by the process of theinvention include the conversion of propylene to acrolein, isobutyleneto methacrolein, alphaor beta-butylene to methyl vinyl ketone, pentene-lor pentene-Z to ethyl vinyl ketone and/or pentene-3-one-2,Z-methyl-butene- 2 to methyl isopropenyl ketone, cyclopentene tocyclopentenone-2, and the like.

It is to be noted that the vinyl-type carbonylic products obtained bythe oxidation of olefins in contact with a solid cuprous oxide catalystare not necessarily those which would be expected from the directsubstitution of an oxygen atom for two hydrogen atoms in the allylposition, that is, for two hydrogen atoms attached to a carbon atomseparated from the double bond by an intervening carbon atom, for inthat case beta-butylene, for example, would form crotonaldehyde and notmethyl vinyl ketone. Instead, the reaction appears to be initiated atthe double bond and proceeds with the elimination of a hydrogen atomfrom the allyl position and a change in position of the double bond.

Straight chain alpha-olefins of three or more carbon atoms when treatedaccording to the present process tend to yield the same products as thecorresponding beta-olefins. Thus, as stated above, alpha-butylene aswell as beta-butylene yields methyl vinyl ketone and pentene-l likepentene-2 yields ethyl vinyl ketone. This is thought to result fromisomerization of these alpha-olefins to the beta-olefins under thereaction conditions.

The compounds of chlorine which are used advantageously in practicingthe process of the present invention are those compounds which possess asubstantial volatility at the temperature of reaction in the presentprocess and which decompose at least in part when brought into con tactwith the cuprous oxide catalyst under the existing conditions ofoperation. Preferably, chlorine compounds having a boiling point atatmospheric pressure below about 400 C. are employed, although lessvolatile compounds of chlorine may at times be used. The compounds ofchlorine which have been found to be of benefit in accordance with theprocess of the present invention may be either organic or inorganic,although it frequently is most advantageous to employ an organiccompound of chlorine. Chlorinated non-aromatic hydrocarbons,particularly those having boiling points below about 250 C., are ofparticular value for use in the present process. 7

As examples of specific compounds'of chlorine which advantageously maybe used in the process of the present invention, reference may be madeto inorganic compounds of chlorine that possess a substantial volatilityat the temperature of reaction and which decompose at least in part whenbrought into contact with the cuprous oxide catalyst under theconditions of operation, such as hydrochloric acid, cupric chloride,ammonium chloride, ferric chloride, and the like, and to organiccompounds of chlorine such as acetyl chloride, propionyl chloride,monochlorbenzene, benzyl chloride, benzoyl chloride, and their analogsand homologs, and, preferably, the chlorinated non-aromatic hydrocarbonssuch as methyl chloride, methylene dichloride, chloroform, carbontetrachloride, ethyl chloride and chlorine substitution products ofethane containing more than one chlorine atom, propyl chloride,isopropyl chloride, the butyl chlorides, amyl chlorides, vinyl chloride,allyl chloride, crotyl chloride, methallyl chloride and analogous andhomologous chlorinated non-aromatic hydrocarbons boiling below about 250C. at atmospheric pressure and which decompose at least in part whenbrought into contact with the cuprous oxide catalyst under the existingconditions of operation. Of the indicated organic compounds, it ispreferred to use isopropyl chloride or allyl chloride in the process ofthe present invention.

It has been found that the beneficial effects obtained in accordancewith the present.invention are quite specific and depend upon the use ofa compound of chlorine such as those referred to above. Surprisingly,compounds as closely related even as the corresponding compounds ofother halogens, i. e., bromine, iodine, and fluorine, do not provide theadvantageous results obtained by the presence of a compound of chlorineduring the catalytic oxidation by means of a cuprous oxide catalyst ofan olefin containing at least three carbon atoms to an unsaturatedcarbonylic compound. The reason for this specificity is not wellunderstood. However, it may be noted that the cuprous oxide catalystitself is quite specific in promoting the oxidation of the olefins tothe carbonylic compounds, other metal oxides, or other oxides of copper,leading to the formation of quite difierent principal products ofreaction. It therefore appears probable that a specificinter-relationship exists between the cuprous oxide catalyst and thecompounds of chlorine that leads to benefaction of the catalyst underthe existing conditions of operation and to consequent improved yieldsof the unsaturated earbonylic compound relative to the amount of olefinsconsumed.

The'cuprous oxide employed in the execution of the process of theinvention preferably is supported on or mixed with a suitable carriermaterial, such as silica gel, silicon carbide porous aggregates, pumiceand the like. Impregnation of the oxide on the carrier may be carriedout, for example, by treating the degassed carrier with a concentratedsolution of cupric nitrate or chloride or with an ammonium compound com-Gil prising copper. as copper ammonium nitrate. The nitrate and ammoniumcompounds may be decomposed to cuprous oxide by first heating the driedcarrier between about 250 C. and 400 C. in a slow stream of air and thenreducing the cupric oxide thus formed to cuprous oxide with hydrogen orother suitable reducing agent. Substantially the same procedure isfollowed in the preparation of the catalyst from the chloride exceptthat repeated oxidation and reduction may be necessary. Cupric oxide iscompletely ineffective when applied in lieu of cuprous oxide in theexecution of the process. It has been found that when the cuprous oxidecatalyst is prepared from cupric chloride as above indicated, sufiicientchlorine compounds ordinarily remain in the catalyst to provide yieldsof carbonylic compounds substantially higher than are obtained with acatalyst prepared from, for instance, cupric nitrate. The effect is notpermanent, however, and tends to diminish as the catalyst is used.However, considerable benefit may be derived from the indicated efiectof the residual chlorine compounds in the event it is desired to use theprocess of the present invention for the preparation of only limitedamounts of unsaturated carbonylic compounds.

According to a preferred mode of executing the process, the olefin to beoxidized is contacted in the vapor state with the supported cuprousoxide in the presence of oxygen or an oxygencontaining gas such as air.The compound of chlorine may be added to either the olefin or to theoxygen or oxygen-containing gas, or, if desired, to the mixed gases. Ifa diluent gas is present in the reaction mixture, the chlorine compoundmay be added either separately to the diluent gas prior to admixturewith the other components, or to the final reaction mixture.

Various means of addin the desired chlorine compound are available andthe present invention is not limited to any specific mode of addition.For example, vapors of the chlorine compound may be metered into thegaseous reaction mixture or one or more of the components thereof, orthe chlorine compound in the liquid state may be introduced into andvolatilized in the vapors of one or more of the components of thereaction mixture. In the event one or more of the components of thereaction mixture are liquid at normal temperatures, the chlorinecompound may be added thereto and volatilized therewith. In the case ofcontinuous operations, a particularly convenient manner of operation isto contact the vapors of at least one of the components of the reactionmixture with the chlorine compound in the liquid state, and to controlthe amount of chlorine compound thereby added by regulation of thetemperature, rate of flow of the vapor, etc.

The amount of chlorine compound thus added in accordance with thepresent invention represents only a minute amount relative to the totalamount of reaction mixture. Generally speaking, there is added an amountless than about 0.40 mole per cent based on the amount of olefinpresent. Larger amounts may have an inhibitory effect on the cuprousoxide catalyst or may react with either the olefin reactant or theproduct in the oxidation process with consequent chlorination of thereactant or product. The addition of such larger amounts of chlorinecompound therefore generally leads to decreased yields of the desiredunsaturated carbonylic compounds, and hence generally is to be avoided.As the amount of added compound of chlorine is decreased from about 0.4mole per cent, there generally occurs an optimum range wherein the yieldof unsaturated carbonylic compound is at a maximum under the otherwiseexisting conditions. Optimum yields thus generally are obtained in thepresence of from about 0.02 to about 0.08 mole per cent of .addedchlorine compound, based upon the amount of olefin present, although theexact range for optimum results has been found to depend to a certainextent upon the particular compound of chlorine that is employed.Beneficial results may be obtained through the addition of as little as0.002 mole per cent of added chlorine compound, based upon the amount'of olefin. By regulating the amount of chlorine compound presentgenerally within the indicated amounts, the process of the presentinvention makes it possible to obtain a substantially higher conversionof consumed olefin to the unsaturated carbonylic compound than isobtained under the otherwise existing conditions of operation in theabsence of a compound of chlorine.

in effecting the process of the present invention, considerable latitudeis permissible in the reaction temperature. However, the reactiontemperature, i. e., the temperature of the catalyst, preferably ismaintained in the range of from about 200 C. to about 450 C. Catalysttemperatures as high as about 600 C. have at times been foundpermissible. The temperature used depends primarily upon the catalyst,the particular olefin being treated, and the correlated conditions ofthe rate of throughput or contact time, and the ratio of olefin tooxygen. Apparent contact times of from about 0.1 sec. to about sec.generally are satisfactory. The apparent contact time may be defined asthe length of time in seconds a unit volume of gas measured under theconditions of reaction is in contact with a unit apparent volume of thecatalyst. It may be calculated, for example, from the apparent volume ofthe catalyst bed, the average temperature of the catalyst, the pressure(if different from atmospheric), and the flow rates of the severalcomponents of the reaction mixture. Molar ratios of olefin to oxygenbetween about 1:1 and 8:1 generally give the most satisfactory results.It has been determined that unless the temperature is kept underreasonable control, the oxidation may proceed to the formation of carbondioxide and water at the expense of the desired product. The temperaturemay be controlled,for example, by diluting the reaction mixture withsteam, by operating with an excess of olefin and/ or by using a carrieror supporting material which is a good heat conductor. Also the cuprousoxide, alone or supported on a suitable carrier material, may be used ina dust or fluidized form and agitated to dissipate the heat of reaction.The reaction may be conducted at any pressure commensurate with thetemperature at which it is desired to operate but usually the reactionis carried out at near atmospheric pressure to avoid the possibility ofencountering possible conditions leading to explosion or autoignition ofthe reaction mixture.

In general, any apparatus of the type suitable for carrying outoxidation reactions in vapor phase may be employed in the execution ofthe process. When operating with a fixed bed catalyst, as is preferred,the apparatus may comprise a catalyst-packed reaction tube or chamberpositioned within a metal block, as an alution, it is preferred to carryout the process in a continuous manner, if desired any unreacted olefinand/or oxygen being recirculated with fresh feed.

The unsaturated carbonyl product or products are isolated from the exitgases from the reaction zone by any appropriate means, the exactprocedure in any given case being determined by the nature and relativeamounts of the other reaction products. Usually the exit gases arescrubbedw'ith cold water or other appropriate solventto removethe-carbonyl product which is subsequently recovered from the solvent byany suitable means as by distillation. The efliciency of the scrubbingoperation may be improved when water is employed as the scrubbing agentby adding a suitable wetting agent, e. g. any soap or soap-likesubstance, to the water. If desired, scrubbing of the reaction gases maybe preceded by an initial cold water quenching thereof, which of itselfmay serve to separate a large portion of the carbonyl product.

Where molecular oxygen is being employed as the oxidizing agent theresidual mixture subsequent to the separation of the carbonyl productmay be treated as with a potassium hydroxide solution of suitablestrength to efiect the removal of any carbon dioxide. The remainder ofthe mixture which comprises any unreacted olefin and oxygen may then berecycled through the reactor. In the event that air is being used as theoxidizing agent in lieu of molecular oxygen, the residual mixture afterseparation of the carbonyl product may be scrubbed with a nonpolarsolvent, e. g. a hydrocarbon fraction such as kerosene, in order torecover unreacted olefin and the remaining gases discarded.

Various phases of the invention are illustrated by the followingexamples:

EXAMPLE I The following experiment was carried out in order to determinethe effects of the presence of minute amounts of isopropyl chloride uponthe oxidation of propylene to acrolein with a soil cuprous oxidecatalyst.

A. Oxidation in the absence of a compound of chlorine One hundred fiftycc. of a cuprous oxide catalyst comprising 0.9 per cent by weight ofcopper in the form of cuprous oxide, on 8-10 mesh silicon carbide porousaggregates was supported in a vertically positioned stainless steelreaction tube having an internal diameter of 0.98 inch and a length of44 inches, provided with externally located heating means, and having a0.25 inch diameter thermocouple well extending coaxially the length ofthe tube. A mixture of air, propylene and water (steam) was preheated toabout 400 C. and passed at a pressure of 10-20 pounds per square inch(gauge) over the catalyst which was maintained at an average temperatureof 460 C. and an average maximum temperature of 590 C.'600 C. Thecomponents of the mixture were present in the following molar ratios:H20/O2, 9-17; CaHc/Oz, 2.0-2.3; and the mixture was passed into contactwith the catalyst for an average contact time of 0.9-1.1 sec.

7 The gases leaving the reaction tube were analyzed and it was foundthat 36 per cent of the propylene consumed had been converted toacrolein.

B. Oxidation in the presence of isopropyl chloride The foregoingexperiment was repeated using the same catalyst and under the sameconditions, but with the addition (to the gaseous mixture entering thereaction tube) of 0.043 mole per cent, based on the propylene, ofisopropyl chloride. In this experiment, it was found that 51 per cent ofthe propylene consumed had been convertedto acrolein, or, in otherwords, the yield of acrolein had been increased by 42 per cent by thepresence of the isopropyl chloride.

EXAMPLEH Propylene was oxidized to acrolein in a manner similar to theexperiments given in Example I, but under the following conditions:

Catalyst: 1.2% Cu as cuprous oxide on silicon carbide porous aggregates.

Reactor tube: inch x 160 inch steel tube surrounded by molten saltmixture to maintain constant temperature.

Flow rates (moles/min): Propylene 0.0623; oxygen 0.033; H2O (steam)0.354.

Salt bath temperature: 412 C.

Maximum temperature: 421 C.

Pressure: Atmospheric.

Isopropyl chloride added to feed (mole based on propylene): 0.10.

Yield of products formed, based on propylene consumed:

EXAMPLE III In this experiment, propylene was oxidized to acroleinwithout added chlorine compound, and then in the presence of minuteamounts of HCl added by bubbling the propylene component of the feedthrough a 19.8% hydrochloric acid solution at room temperature.

Catalyst: 1.06% copper as cuprous oxide on con carbide.

Reactor tube: 4.4 cm. x 51 cm. Pyrex glass tube.

Flow rates (moles/min): Propylene 0.146-0.155;

oxygen 0.0073; steam 0.0680.113.

Temperature: 370 C.

Pressure: Atmospheric.

In the absence of any added chlorine compound, 50.8% of the propyleneconsumed was converted to acrolein. In the presence of about 0.032 moleof HCl, based on the propylene, 69.6% of the propylene consumed wasconverted to acrolein.

EXAMPLE IV Propylene was oxidized to acrolein in the reactor used inExample III in the presence of a catalyst composed of 2.41% copper ascuprous oxide on silicon carbide, at a maximum catalyst temperature of363 C. Flow rates of 0.136 mole per minute of propylene, 0.0073 mole perminute siliof oxygen, and 0.132 mole per minute of H20 (steam) wereemployed. 0.11 mole per cent of allyl chloride, based on the propylene,was added to the reactor feed. 57.6 per cent of the propylene consumedwas converted to acrolein.

Substantially lower conversions of propylene to acrolein were obtainedin the absence of allyl chloride but under otherwise similar conditions.

EXAIWPLEV Isobutylene was oxidized to methacrolein in the presence of acuprous oxide catalyst. In the absence of any added chlorine compoundand at flow rates of 0.068 mole isobutylene per minute, 0.033 mole 0:per minute, and 0.281 mole H1O (steam) per minute, the maximumtemperature recorded in the catalyst bed was 331 C., and 10.0% of theisobutylene fed was found to have been converted to methacrolein(determined as total aldehydes, which were predominantly methacrolein).In the presence of 0.09 mole per cent isopropyl chloride based on the,isobutylene and at flow rates of 0.066 mole isobutylene per minute,0.033 mole O2 perminute, and 0.354 mole water (steam) per minute, themaximum temperature noted in the catalyst bed was 426 C., and 18.1 percent of the isobutylene fed was found to have been converted tomethacrolein (determined as total aldehydes).

EXAMPLE VI Experiments in fluidized fixed bed reactor The reactor wasconstructed of mild steel and I consisted essentially of a verticallypositioned tube, the lower 23 inches of its length having an insidediameter of 2 inches, and the upper 18 inches of its length having aninside diameter of 4 inches. The lower portion was surrounded byelectrical heating elements. 310 grams of the catalyst, which contained8.2 per cent copper in the form of cuprous oxide, on 320 mesh siliconcarbide, were placed in the reactor, and the reactor feed passedupwardly through the catalyst bed at a rate sufllcient to suspend thecatalyst in the gas stream in the narrow portion of the reactor tube.

At a temperature of 400 C., at flow rates of 8 moles propylene per hour,1.13 moles oxygen (as air) per hour, and 20 moles H2O (steam) per hour,and at a pressure of 4-6 pounds per square inch, it was found that inthe absence of a compound of chlorine there was obtained a 56 per centyield of acrolein, based on the propylene consumed. v

At a temperature of 402 C., at flow rates of 8 moles propylene per hour,1.04 moles oxygen (as air) per hour, and 20 moles H2O (steam) per hour,and with the addition to the feed of 0.025 mole per cent isopropylchloride based on the propylene, there was obtained a yield of acroleinof '70 per cent, based on the propylene consumed.

We claim as our invention:

1. A process of producing methacrolein which comprises reacting agaseous mixture comprising isobutylene, oxygen, and from about 0.002mole per cent to about 0.2 mole per cent based on the isobutylene ofallyl chloride, in contact with a solid cuprous oxide catalystmaintained within the temperature range of from about 200 C. to about600 C., under correlated conditions of reaction temperature, time ofcontact of the mixture with the catalyst, and relative amounts ofisobutylene and oxygen in the mixture, to provide methacrolein as theprincipm product of reaction, thereby obtaining higher relativeconversion of consumed isobutylene to methacrolein than is obtainedunder the existing conditions in the absence of the allyl chloride.

2. A process of producing acrolein which comprises reacting agaseousmixture comprising propylene, oxygen, and from about 0.002 moleper cent to about 0.2 mole per cent based on the propylene of allylchloride, in contact with a solid cuprous oxide catalyst maintainedwithin the temperature range of from about 200 C. to about 600 C., undercorrelated conditions of reaction temperature. time of contact of themixture with the catalyst, and relative amounts of propylene and oxygenin the mixture, to provide acrolein as the principal product ofreaction, thereby obtaining higher relative conversion of consumedpropylene to acrolein than is obtained under the existing conditions inthe absence of the allyl chloride.

3. A process of producing methacrolein which comprises reacting agaseous mixture com risinc isobutylene. oxygen, and from about 0.002mole per cent to about 0.2 mole per cent based on the isobutylene ofisonropyl chloride. in con tact with a solid cuprous oxide catalystmaintained within the temperature range of from about 200 C. to about600 C., under correlated conditions of reaction temperature. time ofcontact of the mixture with the catalyst, and relative amounts ofisobutylene and oxygen in the mixture. to provide methacrolein as theprincipal product of reaction, thereby obtaining higher relativeconversion of consumed isobutylene to methacrolein than is obtainedunder the existing conditions in the absence of the isopropyl chloride.

4. A process of producing acrolein which comprises reacting a gaseousmixture comprising propylene, oxygemand from about 0.002 mole per centto about 0.2 mole percent based on the propylene of isopropyl chloride,in contact with a solid cuprous oxide catalyst maintained within thetemperature range of from about 200 C. to about 600 C., under correlatedconditions of reaction temperature, time of contact of the mixture withthe catalyst. and relative amounts of propylene and oxygen in themixture, to provide acrolein as the principal product of reaction,thereby obtaining higher relative conversion of consumed propylene toacrolein than is obtained under the existing conditions in the absenceof the isopropyl chloride.

5. A process of producing an unsaturated carbonylic compound of theclass consisting of the unsaturated aldehydes and the unsaturatedketones, which comprises passing a gaseous mixture comprising oxygen, anolefin containing at least three carbon atoms, and from about 0.002 moleper cent to about 0.2 mole per cent. based on the olefins, of analiphatic organic chloride into contact with a solid cuprous oxidecatalyst maintained within the temperature range of from about 200 C. toabout 600 C., under correlated conditions of reaction temperature, timeof contact of the mixture with the catalyst, and relative amounts ofolefin and oxygen in the mixture adapted to produce an unsaturatedcarbonylic compound containing the same number of carbon atoms as theolefin as the principal product of reaction.

6. A process of producing an unsaturated carbonylic compound of theclass consisting of the unsaturated aldehydes and the unsaturatedketones, which comprises adding to at least one oi. the components of agaseous mixture comprising 10 an olefin containing at least three carbonatoms, and oxygen, a minute amount less than about 0.40 mole per centbased on the olefin of hydrogen chloride, thereafter passing the gaseousmixture containing the hydrogen chloride into contact with a solidcuprous oxide catalyst maintained within the temperature range of fromabout 200 C. to about 600 C., under correlated conditions of reactiontemperature, time of contact of themixture with the catalyst, andrelative amounts of olefin and oxygen in the mixture adapted to providethe unsaturated carbonylic compound as the principal product ofreaction, the added hydrogen chloride providing a higher relativeconversion of consumed olefin to unsaturated carbonylic compound than isobtained under the existing conditions in the absence of the hydrogenchloride.

7. A process of producing methacrolein which comprises adding to atleast one of the components of a gaseous mixture comprising isobutyleneand oxygen, a minute amount less than about 0.4 mole per cent based onthe isobutylene of an aliphatic organic chloride, thereafter passing thegaseous mixture containing the aliphatic organic chloride into contactwith a solid cuprous oxide catalyst maintained within the temperaturerange of from about 200 C. to about 600 C., under correlated conditionsof reaction temperature, time of contact of the mixture with thecatalyst, and relative amounts of isobutylene and oxygen in the mixtureadapted to provide-methacrolein as the principal product of reaction,the added compound of chlorine providing a higher relative conversion ofconsumed isobutylene to methacrolein than is obtained under the existingconditions in the absence of the compound of of a gaseous mixturecomprising propylene and 7 oxygen, a minute amount less than about 0.4mole per cent based on the propylene, of an aliphatic organic chloride,thereafter passing the gaseous mixture containing the compound ofchlorine into contact with a solid cuprous oxide catalyst maintainedwithin the temperature range of from about 200 C. to about 600 C., undercorrelated conditions of reaction temperature, time of contact of themixture with the catalyst, and relative amounts of propylene and oxygenin the mixture adapted to provide acrolein as the principal product ofreaction, the added compound of chlorine providing a higher relativeconversion of consumed propylene to acrolein than is obtained under theexisting conditions in the absence of the compound of chlorine.

9. A process of producing an unsaturated carbonylic compound of theclass consisting of the unsaturated aldehydes and the unsaturatedketones, which comprises adding to at least one of the components oi? agaseous mixture comprising an olefin containing at least three carbonatoms, and oxygen, 9. minute amount less than about 0.4 mole per centbased on the olefin, of an aliphatic organic chloride, thereafterpassing the gaseous mixture containing the organic chloride into contactwith a solid cuprous oxide catalyst maintained within the temperaturerange of from about 200 C. to about 600 C., under correlated conditionsof reaction temperature, time of contact of the mixture with thecatalyst, and relative amounts of olefin and oxygen in the mixtureadapted to provide the unsaturated carbonylic compound as the principalproduct of reaction,

the added organic chlorideproviding a higher relative conversion ofconsumed olefin to unsaturated carbonylic compound than is obtainedunder the existing conditions in the absence of the chloride.

10. A process of producing methacrolein, which comprises adding to atleast one of the components of a gaseous mixture comprising isobutyleneand oxygen, a minute amount of a chlorine compound having a boilingpoint under atmospheric pressure less than about 400 C., thereafterpassing the gaseous mixture containing the chlorine compound intocontact with a solid cuprous oxide catalyst maintained within thetemperature range of from about 200 C. to about 600 C., under correlatedconditions of reaction temperature, time of contact of the mixture withthe catalyst, and relative amounts of isobutylene and oxygen in themixture adapted to provide methacrolein as the principal product ofreaction, and regulating the amount of the chlorine compound added toprovide a higher relative conversion of consumed isobutylene tomethacrolein than is obtained under the existing conditions in theabsence of the chlorine compound.

11. A process of producing acrolein, which comprises adding to at leastone of the components of a gaseous mixture comprising propylene andoxygen, a minute amount of a compound of chlorine, thereafter passingthe gaseous mixture containing, the compound of chlorine into contactwith a solid cuprous oxide catalyst maintained within the temperaturerange or from about 200 C. to about 600 C., under correlated conditionsof reaction temperature, time of contact of the mixture with thecatalyst, and relative amounts of propylene and oxygen in the mixtureadapted to provide acrolein as the principal product of reaction, andregulating the amount of the compound of chlorlne added to provide ahigher relative conver.. sion of consumed propylene to acrolein than isobtained under the existing conditions in the airsence of the compoundof chlorine.

12. A process of producing an unsaturated carbonylic compound of the theclass consisting of the unsaturated aldehydes and the .unsaturatedketones, which comprises adding to at least one of the components of agaseous mixture comp an olefin containing at least three carbon atoms,and oxygen, a minute amount of a compound of chlorine, thereafterpassing the gaseous mixture containing the compound of chlorine intocontact with a cuprous oxide catalyst maintained within the temperaturerange of from about 200 C. to about 600 0., under correlated conditionsof reaction temperature, time of contact of the mixture with thecatalyst, and relative amounts of olefin and oxygen in the mixtureadapted to pro-' vide the unsaturated carbonylic compound of the classconsisting of the unsaturated aldehydes and the unsaturated ketones asthe principal product or reaction, and regulating the amount of thecompound of chlorine added to provide a higher relative conversion 01'consumed olefin to unsaturated carbonylic compound than is obtainedunder the existing conditions in the absence of the compound ofchlorine.

13. A process of producing an unsaturated carbonylic compound of theclass consisting of the unsaturated aldehydes and the unsaturatedketones, which comprises bringing a gaseous mixture comprising an olefincontaining at least three carbon atoms, and oxygen into contact with asolid cuprous oxide catalyst in the presence of a minute amount of achlorinated hydrocarbon having a boiling point below about 250 0., the

cuprous oxide catalyst being maintained at a temperature between about200 C. and about 600 0., thereby producing the unsaturated carbonyliccompound of the class consisting of the unsaturated aldehydes and theunsaturated ketones as the principal product of reaction, and regulatingthe amount 01' the chlorinated hydrocarbon to provide a higher relativeconversion of consumed olefin to unsaturated carbonylic compound than isobtained under the existing conditions in the absence of the chlorinatedhydrocarbon.

14. A process of producing methacrolein, which comprises contacting agaseous mixture comprising isobutylene and oxygen with a solid cuprousoxide catalyst in the presence of a minute amount of a chlorinecompounr, having a boiling point under atmospheric pressure below about400 C., the cuprous oxide catalyst being maintained at a temperaturebetween about 200 C. and about 600 0., thereby producing methacrolein asthe principal product of reaction, and regulating the amount of thechlorine compound to provide a higher relative conversion or theisobutylene consumed to methacrolein than is obtained under the existingconditions in the absence of the chlorine compound.

15. A process of producing acrolein which comprises contacting a gaseousmixture comprising propylene and oxygen with a solid cuprous oxidecatalyst in the presence of a minute amount of a chlorine compoundhaving a boiling point under atmospheric pressure below about 400 C.,the cuprous oxide catalyst being maintained at a temperature betweenabout 200 C. and about 600 C., thereby producing acrolein as theprincipal product of reaction, and regulating the amount of the chlorinecompound to provide a higher relative conversion of the propyleneconsumed to acrolein than is obtained under the existing conditions inthe absence of the chlorine compound.

16. A process of producing an unsaturated carbonylic compound of theclass consisting of the unsatin'ated aldehydes and the unsaturatedketones, which comprises contacting a gaseous mix ture comprising anolefin containing at least three carbon atoms, and oxygen with a solidcuprous oxide catalyst in the presence of a minute amount of a chlorinecompound having a boiling point under atmospheric pressure below about400 C., the cuprous oxide catalyst being maintained at a. temperaturebetween about 200 C. and about 600 0., thereby producing the unsaturatedcarbonylic compound of the class consisting of the unsaturated aldehydesand the unsaturated ketones as the principal product of reaction, andregulating the amount of the chlorine compound to provide a higherrelative conversion or consumed olefin to unsaturated carbonyliccompound than is obtained under the existing conditions in the absenceof the chlorine compound.

GEORGE W. HEARNE. MERRILL L. ADAMS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 20,370 Lefort Ma 18, 19372,265,948 Loder Dec. 9, 1941 2,279,470 Law et al Apr. 14, 1942 2,430,443Becker Nov. 11. 1947

